ppm question (1 Viewer)

[Dedopcat]

a bottle of cream has 8.20ppm aluminium. The bottle contains 9 g of cream

determine the mass of al in the cream


please show all working

thankyou so much

 

[nightweaver066]

ppm = mg/kg (milligrams/kilogram) (difference of powers by 10^6 to give 'parts per million')

Now, 8.20ppm = 8mg/kg
= (8 x 10^-3)g/1000g

Dividing top and bottom by 1000

= (8 x 10^-6)g/g

Multiplying top and bottom by 9

= (72 x 10^-6)g/9g

= (7.2 x 10^-5)g/9g

Therefore 7.2 x 10^-5 g of Al in the cream.